Image sensors have become ubiquitous and are now widely used in digital cameras, cellular phones, security cameras, as well as, medical, automobile, and other applications. As image sensors are integrated into a broader range of electronic devices and their functionally continually expands, it is desirable to enhance the performance metrics of image sensors in as many ways as possible (e.g., resolution, power consumption, dynamic range, and the like) through both device architecture design as well as through post-image acquisition processing.
The typical image sensor operates in response to image light from an external scene being incident upon the image sensor. The image sensor includes an array of pixels having photosensitive elements (e.g., photodiodes) that absorb a portion of the incident image light and generate image charge upon absorption of the image light. The image charge of each of the pixels may be measured as an output voltage of each pixel that varies as a function of the incident image light. In other words, the amount of image charge generated is proportional to the intensity of the image light, which is utilized to produce a digital image (i.e., image data) representing the external scene. However, the image sensor may generate an inaccurate representation of the external scene due to dark current influencing the image charge (e.g., adding to the output voltage) measured from the individual pixels of the image sensor, which may hinder the image sensor from producing digital images that faithfully reproduce the optical characteristics (e.g., intensity, color, and the like) of the external scene.